Kelly met for the first time with the parents of 18-year-old Ramarley Graham, who was killed in his bathroom last month.
A narcotics officer said Graham appeared to be dealing drugs.
Graham's parents will speak during the vigil at the family's home on East 229th Street.
Graham was unarmed when he was shot Feb. 2 by a drug enforcement officer who chased him into his Bronx house, shooting him in a bathroom. The officer and his sergeant are on desk duty while prosecutors investigate. It was the third time in a week that police had fatally shot a suspect.
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